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Soil organic matter dynamics: a biological perspective derived from the use of compound‐specific isotopes studies
Author(s) -
Gleixner Gerd
Publication year - 2013
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1007/s11284-012-1022-9
Subject(s) - decomposer , soil organic matter , organic matter , environmental science , soil carbon , stable isotope probing , ecology , isotopes of carbon , soil biology , bioturbation , lability , carbon cycle , soil water , environmental chemistry , soil science , chemistry , biology , total organic carbon , ecosystem , microorganism , sediment , paleontology , genetics , bacteria , biochemistry
Current attempts to explain the persistence of carbon in soils focuses on explanations such as the recalcitrant plant residues and the physical isolation of substrates from decomposers. A pool of organic matter that can persist for centuries to millennia is hypothesized because of the evidence provided by the persistence of pre‐disturbance C in fallow or vegetation change experiments, and the radiocarbon age of soil carbon. However, new information, which became available through advances in the ability to measure the isotope signatures of specific compounds, favors a new picture of organic matter dynamics. Instead of persistence of plant‐derived residues like lignin in the soil, the majority of mineral soil is in molecules derived from microbial synthesis. Carbon recycled multiple times through the microbial community can be old, decoupling the radiocarbon age of C atoms from the chemical or biological lability of the molecules they comprise. In consequence is soil microbiology, a major control on soil carbon dynamics, which highlights the potential vulnerability of soil organic matter to changing environmental conditions. Moreover, it emphasizes the need to devise new management options to restore, increase, and secure this valuable resource.